JP4172269B2 - Internal combustion engine equipped with a heat storage device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an internal combustion engine having a heat storage device that stores heat of a heat medium circulating in the internal combustion engine.
[0002]
[Prior art]
When an internal combustion engine mounted in an automobile or the like is started in a cold state, the wall surface temperature of the intake port, the combustion chamber, etc. becomes low, so that it is difficult for the fuel to atomize and flame extinguishing occurs at the periphery of the combustion chamber This will cause a decrease in startability and a deterioration in exhaust emission.
[0003]
Conventionally, in such a water-cooled internal combustion engine, a heat storage tank that stores the heat of the cooling water and the cooling water (hot water) in the heat storage tank when the internal combustion engine is cold-started are used in the water-cooled internal combustion engine. A heat storage device having a mechanism to circulate is proposed.
[0004]
On the other hand, in recent internal combustion engines for vehicles, electronic control of various engine components represented by fuel injection valves, spark plugs, intake throttle valves (throttle valves) and the like has been promoted. As a parameter for determining the control value, the temperature of the cooling water circulating through the internal combustion engine may be used.
[0005]
For example, in fuel injection control and ignition control, the basic fuel injection amount and basic ignition timing are calculated using engine speed, engine load, etc. as parameters, and a correction value (water temperature correction value) corresponding to the coolant temperature is calculated. The Subsequently, a water temperature correction value is added to the basic fuel injection amount and basic ignition timing to determine the final fuel injection amount and ignition timing.
[0006]
By the way, when the electronic control technology and the heat storage system described above are combined, the control value is set in consideration of the temperature of the cooling water stored in the heat storage tank in addition to the temperature of the cooling water circulating through the internal combustion engine. It is necessary to decide.
[0007]
This is because when the hot water stored in the heat storage tank is supplied to the internal combustion engine, the cooling water temperature on the internal combustion engine side rapidly rises, whereas the water temperature sensor for detecting the cooling water temperature is This is because a so-called response delay occurs that makes it impossible to follow the rapid rise in temperature.
[0008]
Conventionally, in such an internal combustion engine having a heat accumulator that introduces a part of cooling water for cooling the internal combustion engine and stores the cooling water in a heat storage state, the inside of the heat accumulator or the heat accumulator A temperature sensor that detects the temperature of the coolant near the outlet of the engine, and if the detected temperature of the temperature sensor is higher than a predetermined temperature when the internal combustion engine is started at a low temperature, the fuel increase correction amount at start-up and / or the fuel increase correction amount during warm-up is reduced There has been proposed one that includes a correction command means for correcting on the side (see, for example, Patent Document 1).
[0009]
[Patent Document 1]
JP 10-37785 A
[Problems to be solved by the invention]
By the way, the above-described conventional technique only changes the fuel increase correction amount based on whether or not the coolant temperature of the heat accumulator at a low temperature start of the internal combustion engine is higher than a predetermined temperature. The actual temperature is not reflected in the fuel injection correction amount. Therefore, it cannot be said that the above-described conventional technique realizes highly accurate fuel injection control.
[0010]
The present invention has been made in view of the above circumstances, and in an internal combustion engine having a heat storage device, it is intended to improve the control accuracy of the internal combustion engine using the state of a heat medium typified by cooling water as a parameter. Objective.
[0011]
[Means for Solving the Problems]
The gist of the present invention is that the heat medium temperature (hereinafter referred to as the heat retention heat medium) stored in the heat storage tank is supplied to the internal combustion engine when the heat medium (hereinafter referred to as the heat retention heat medium) is supplied to the internal combustion engine (hereinafter referred to as the engine side heat medium). The temperature of the heat medium supplied from the heat storage tank to the internal combustion engine is estimated based on the temperature of the heat retaining heat medium and the temperature of the heat retaining heat medium, and the estimated value of the heat medium flow, the engine side heat medium temperature, the heat retaining heat medium temperature, In the technique for controlling the internal combustion engine using the above as a parameter, a guard value is set to the estimated value of the heat medium flow rate.
[0012]
Therefore, an internal combustion engine equipped with a heat storage device according to the present invention includes an engine side temperature detection means for detecting the temperature of the heat medium flowing through the internal combustion engine, and a tank side for detecting the temperature of the heat medium inside or at the outlet of the heat storage tank. When a heat medium is supplied from the temperature detection means and the heat storage tank to the internal combustion engine, the heat medium is supplied from the heat storage tank to the internal combustion engine based on the detection value of the engine side temperature detection means and the detection value of the tank side temperature detection means. A heat medium flow estimator for estimating the flow rate of the heat medium, and when the estimated value of the heat medium flow estimator is a specific value or less, the estimated value is set as a flow rate of the heat medium, and the heat medium flow estimator When the estimated value exceeds a specific value, a heat medium flow guard means for setting the specific value as a flow rate of the heat medium, a detection value of the engine side temperature detection means, a detection value of the tank side temperature detection means, According to the setting value of the fine the heat medium flow guard means is to comprise a control value determining means for determining a control value related to control of the internal-combustion engine.
[0013]
When the heat retaining heat medium in the heat storage tank is supplied to the internal combustion engine, the internal combustion engine is rapidly heated by the heat of the heat retaining heat medium. The temperature increase rate of the internal combustion engine at that time increases, for example, as the difference between the engine-side heat medium temperature before the supply of the heat retaining heat medium and the heat retaining heat medium temperature increases, and conversely, the engine-side heat before the heat retaining heat medium supply. The smaller the difference between the medium temperature and the heat retaining heat medium temperature, the slower.
[0014]
That is, the relationship between the engine-side heat medium temperature and the heat-retaining heat medium temperature before supplying the heat-retaining heat medium is deeply involved in the temperature of the internal-combustion engine when the heat-retaining heat medium is supplied from the heat storage tank to the internal combustion engine. It can be said that.
[0015]
Further, under the situation where the heat retaining heat medium is supplied from the heat storage tank to the internal combustion engine, the temperature increase rate of the internal combustion engine increases as the flow rate of the heat retaining heat medium supplied from the heat storage tank to the internal combustion engine increases. As the flow rate of the heat retaining heat medium supplied to the internal combustion engine decreases, the temperature increase rate of the internal combustion engine decreases.
[0016]
For this reason, the temperature of the internal combustion engine in a state where the heat insulation heat medium is supplied from the heat storage tank to the internal combustion engine includes the flow rate of the heat insulation heat medium supplied from the heat storage tank to the internal combustion engine (hereinafter referred to as the heat insulation heat medium flow rate). It can be said that there is a correlation.
[0017]
Therefore, it can be said that the temperature of the internal combustion engine when the heat retaining heat medium is supplied from the heat storage tank to the internal combustion engine is correlated with the engine side heat medium temperature, the heat retaining heat medium temperature, and the heat retaining heat medium flow rate.
[0018]
Here, the above-described heat retaining heat medium flow rate can be estimated from the time required for the heat retaining heat medium flowing out of the heat storage tank to reach the internal combustion engine.
[0019]
When the heat medium flows out of the heat storage tank, a low-temperature heat medium flows into the heat storage tank and pushes out the heat retaining heat medium in the heat storage tank. The temperature of the heat medium inside decreases.
[0020]
Therefore, as a method for specifying the time when the heat medium flows out from the heat storage tank (hereinafter referred to as the heat retaining heat medium outflow time), the temperature sensor is disposed at the outlet of the heat storage tank and the detected value of the temperature sensor is increased. Examples thereof include a method of considering the heat insulation heat medium outflow time, or a method of disposing the temperature sensor in the heat storage tank and considering the time when the detected value of the temperature sensor is lowered as the heat insulation heat medium outflow timing.
[0021]
In addition, as a method of specifying the time when the heat retaining heat medium flowing out from the heat storage tank reaches the internal combustion engine (hereinafter referred to as the heat retaining heat medium arrival time), the time when the temperature of the heat medium flowing through the internal combustion engine rises is kept warm. A method that is regarded as the heat medium arrival time can be exemplified.
[0022]
By the way, when the heat insulation heat medium arrival time is specified by the method as described above, if a heat medium having a temperature higher than the engine side heat medium temperature exists in a part of the path from the heat storage tank to the internal combustion engine, There is a possibility that the time when the high temperature heat medium flows into the internal combustion engine is erroneously determined as the time when the heat retaining heat medium reaches.
[0023]
That is, there is a possibility that it is erroneously determined that the heat retaining heat medium from the heat storage tank has reached the internal combustion engine even though the heat retaining heat medium flowing out from the heat storage tank has not reached the internal combustion engine.
[0024]
When such an erroneous determination occurs, the heat retaining heat medium flow rate estimated by the heat medium flow rate estimating means (hereinafter referred to as the heat retaining heat medium flow rate estimated value) becomes the actual heat retaining heat medium flow rate (hereinafter referred to as the actual heat retaining heat medium flow rate). It is assumed that the temperature of the internal combustion engine is considered higher than the actual temperature. In such a case, when the control value for the control of the internal combustion engine is determined based on the engine-side heat medium temperature, the heat retaining heat medium temperature, and the heat retaining heat medium flow rate estimated value, the control value described above is the actual value of the internal combustion engine. The value may not be suitable for the temperature.
[0025]
On the other hand, in the internal combustion engine provided with the heat storage device according to the present invention, when the heat retaining heat medium flow rate estimated value estimated by the heat retaining heat medium flow rate estimating means exceeds the specific value, the specific value described above is used as the heat retaining heat medium. The flow rate is set, and the control value for controlling the internal combustion engine is determined based on the specific value, the engine-side heat medium temperature, and the heat retaining heat medium temperature.
[0026]
According to such a configuration, even if it is erroneously determined that the heat retaining heat medium from the heat storage tank has reached the internal combustion engine even though the heat retaining heat medium flowing out from the heat storage tank has not reached the internal combustion engine, The heat retaining heat medium flow rate used for determining the control value is not excessively increased with respect to the actual heat retaining heat medium flow rate.
[0027]
As a result, the temperature of the internal combustion engine is not considered to be excessively higher than the actual temperature, and a decrease in controllability of the internal combustion engine is suppressed.
[0028]
In addition, since the heat retaining heat medium flow rate is affected by the discharge amount of the pump mechanism for circulating the heat medium and the viscosity of the heat medium, the specific values in the present invention are the discharge amount of the pump mechanism, the viscosity of the heat medium, and the like. May be determined as a parameter.
[0029]
For example, the specific value is set to be larger as the discharge amount of the pump mechanism is increased and / or the viscosity of the heat medium is decreased, and is set to be smaller as the discharge amount of the pump mechanism is decreased and / or the viscosity of the heat medium is increased. You may make it do.
[0030]
The discharge amount of the pump mechanism depends on the battery voltage if the pump mechanism is an electric pump using a battery voltage as a drive source, and the pump mechanism uses a rotational torque of the output shaft of the internal combustion engine as a drive source. If so, it depends on the engine speed. That is, the discharge amount of the electric pump increases as the battery voltage increases and decreases as the battery voltage decreases, and the discharge amount of the mechanical pump increases as the engine speed increases and decreases as the engine speed decreases.
[0031]
The viscosity of the heat medium decreases as the temperature of the heat medium increases, and increases as the temperature of the heat medium decreases. Since the temperature of the heat medium at the time of supplying the heat retaining heat medium has a correlation with the outside air temperature and the engine side heat medium temperature, the higher the outside air temperature and / or the engine side heat medium temperature, the lower the viscosity of the heat medium. Alternatively, the viscosity of the heat medium increases as the engine-side heat medium temperature decreases.
[0032]
Therefore, in the internal combustion engine provided with the heat storage device according to the present invention, the specific value is set using at least one of the outside air temperature, the engine side heat medium temperature, the battery voltage, and the engine speed at the start of supply of the heat retaining heat medium as parameters. You may make it do.
[0033]
The present invention also provides an engine side temperature detecting means for detecting the temperature of the heat medium flowing through the internal combustion engine, a tank side temperature detecting means for detecting the temperature of the heat medium inside or at the outlet of the heat storage tank, and the internal combustion engine from the heat storage tank. Heat for estimating the flow rate of the heat medium supplied from the heat storage tank to the internal combustion engine based on the detection value of the engine side temperature detection means and the detection value of the tank side temperature detection means when the heat medium is supplied to the engine Based on the detected value of the medium flow rate estimating means, the engine side temperature detecting means, the detected value of the tank side temperature detecting means, and the estimated value of the heat medium flow rate estimating means, the actual heat medium flowing through the internal combustion engine Actual engine side temperature estimating means for estimating the temperature, and when the deviation between the detected value of the engine side temperature detecting means and the estimated value of the actual engine side temperature estimating means is less than a specific value, the actual engine side temperature estimating means Guess When the deviation between the detected value of the engine side temperature detecting means and the estimated value of the actual engine side temperature estimating means exceeds a specific value, the value is set as the detected value of the engine side temperature detecting means. Engine-side temperature guard means for setting a value obtained by adding a specific value as engine-side temperature; and control value determining means for determining a control value related to control of the internal combustion engine according to a set value of the engine-side temperature guard means. It may be.
[0034]
The gist of the present invention is that the detection value of the engine side detection means for detecting the temperature of the heat medium flowing through the internal combustion engine (hereinafter referred to as the engine side temperature detection value) when the heat retaining heat medium of the heat storage tank is supplied to the internal combustion engine. ) And the temperature of the heat insulation heat medium, the flow rate of the heat insulation heat medium supplied from the heat storage tank to the internal combustion engine is estimated, and based on the heat insulation heat medium flow rate estimated value, the engine side temperature detection value, and the heat insulation heat medium temperature In the technology for estimating the actual temperature of the heat medium flowing through the internal combustion engine (hereinafter referred to as the actual engine side temperature) and controlling the internal combustion engine using the estimated value of the actual engine side temperature as a parameter, the actual engine side This is in setting a guard value for the estimated temperature value.
[0035]
When the actual engine side temperature is estimated using the heat insulation heat medium flow rate estimated value as a parameter, if the heat insulation heat medium flow rate estimated value is considered to be excessively larger than the actual heat retention heat medium flow rate, the engine side temperature estimated value is It is assumed that the temperature is higher than the actual engine temperature.
[0036]
On the other hand, when a guard value is set for the actual engine-side temperature estimated value, even if it is considered that the heat-retaining heat medium flow rate estimated value is excessively larger than the actual heat-retaining heat medium flow rate, The estimated temperature is no longer considered excessively higher than the actual temperature. As a result, a decrease in controllability of the internal combustion engine is suppressed.
[0037]
In the present invention, examples of the control value related to the control of the internal combustion engine include a fuel injection amount, a fuel injection timing, an ignition timing, and an opening degree of an intake throttle valve (throttle valve).
[0038]
Examples of the heat medium according to the present invention include cooling water and lubricating oil circulating in the internal combustion engine.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of an internal combustion engine having a heat storage device according to the present invention will be described with reference to the drawings.
[0040]
FIG. 1 is a diagram showing a schematic configuration of a cooling system of an internal combustion engine to which the present invention is applied.
[0041]
The cylinder head 1a and the cylinder block 1b of the internal combustion engine 1 are respectively formed with a head side cooling water passage 2a and a block side cooling water passage 2b for circulating cooling water as a heat medium according to the present invention. The cooling water channel 2a and the block side cooling water channel 2b communicate with each other.
[0042]
A first cooling water channel 4 is connected to the head side cooling water channel 2 a, and the first cooling water channel 4 is connected to a cooling water inlet of the radiator 5. A cooling water outlet of the radiator 5 is connected to a thermostat valve 7 via a second cooling water channel 6.
[0043]
In addition to the second cooling water channel 6, a third cooling water channel 8 and a bypass water channel 9 are connected to the thermostat valve 7. The third cooling water channel 8 is connected to an intake port of a mechanical water pump 10 that is attached to the internal combustion engine 1 and uses a rotational torque of a crankshaft as a drive source. The block side cooling water channel 2b is connected. On the other hand, the bypass water channel 9 is connected to the head side cooling water channel 2a.
[0044]
A heater hose 11 is connected in the middle of the first cooling water channel 4 connecting the head side cooling water channel 2 a and the radiator 5. The heater hose 11 is connected to the thermostat valve 7 and the mechanical water pump 10. It is connected to the third cooling water channel 8 in between.
[0045]
In the middle of the heater hose 11, a heater core 12 for exchanging heat between the cooling water and the air for heating the vehicle interior is disposed.
[0046]
A first bypass passage 13 a is connected to the heater hose 11 located between the heater core 12 and the third cooling water passage 8. The first bypass passage 13 a is connected to the cooling water suction port of the electric water pump 14.
[0047]
The electric water pump 14 is a water pump that operates using the output voltage of the battery 100 as a drive source, and is configured to discharge the cooling water sucked from the cooling water suction port at a predetermined pressure from the cooling water discharge port. Yes.
[0048]
The cooling water discharge port of the electric water pump 14 is connected to the cooling water inlet 15a of the heat storage tank 15 through the second bypass passage 13b. The heat storage tank 15 is a container that stores the cooling water while storing the heat of the cooling water. When new cooling water flows from the cooling water inlet 15a, the heat storage tank 15 is stored in the heat storage tank 15 instead. The high-temperature cooling water is configured to be discharged from the cooling water outlet 15b.
[0049]
A third bypass passage 13 c is connected to the cooling water outlet 15 b of the heat storage tank 15, and this third bypass passage 13 c is connected to the heater hose 11 located between the heater core 12 and the first cooling water passage 4. Has been.
[0050]
In addition, in the heater hose 11 located between the heater core 12 and the 1st cooling water channel 4, the site | part by the side of the 1st cooling water channel 4 is called the 1st heater hose 11a on the basis of the connection site | part with the 3rd bypass channel 13c. A portion on the heater core 12 side is referred to as a second heater hose 11b. Further, in the heater hose 11 positioned between the heater core 12 and the third cooling water passage 8, a portion on the heater core 12 side with reference to a connection portion with the first bypass passage 13a is referred to as a third heater hose 11c, and The part on the 3 cooling water channel 8 side shall be referred to as a fourth heater hose 11d.
[0051]
A flow path switching valve 16 is provided at a connection portion between the third heater hose 11c, the fourth heater hose 11d, and the first bypass passage 13a. The flow path switching valve 16 is a valve that selectively switches between all the conduction of the three passages and the blocking of any one of the three passages. The flow path switching valve 16 is driven by an actuator composed of, for example, a step motor.
[0052]
A tank outlet water temperature sensor 17 for detecting the temperature of the cooling water flowing out from the heat storage tank 15 is attached to the vicinity of the cooling water outlet 15b of the heat storage tank 15 in the third bypass passage 13c. This tank outlet water temperature sensor 17 is an embodiment of the tank side temperature detecting means according to the present invention.
[0053]
An engine side water temperature sensor 18 for detecting the temperature of the cooling water flowing in the first cooling water channel 4 is attached in the vicinity of the connection portion of the first cooling water channel 4 to the head side cooling water channel 2a. The engine-side water temperature sensor 18 is an embodiment of the engine-side temperature detecting means according to the present invention.
[0054]
An electronic control unit (ECU) 19 for controlling the internal combustion engine 1 and the cooling system is provided in the cooling system of the internal combustion engine 1 configured as described above. The ECU 19 is an arithmetic and logic circuit including a CPU, a ROM, a RAM, a backup RAM, and the like.
[0055]
The ECU 19 is electrically connected to a tank outlet water temperature sensor 17, an engine side water temperature sensor 18, a battery 100, and the like. Furthermore, the electric water pump 14 and the flow path switching valve 16 are connected to the ECU 19 via electric wiring.
[0056]
The ECU 19 can control the electric water pump 14 and the flow path switching valve 16 using the output signal values of the various sensors described above as parameters, and can also control a fuel injection valve, a spark plug, a throttle valve, and the like (not shown) of the internal combustion engine 1. It is possible.
[0057]
For example, when the internal combustion engine 1 is cold-started, the ECU 19 executes preheating control for preheating the internal combustion engine 1 prior to starting the internal combustion engine 1.
[0058]
In the preheating control, when the internal combustion engine 1 is cold-started, the ECU 19 starts the internal combustion engine 1 under a situation where, for example, the output signal value of the engine-side water temperature sensor 18 is less than a certain temperature (for example, 50 ° C.). If this is the case, preheating control for preheating the internal combustion engine 1 is executed prior to starting.
[0059]
In the preheating control, the ECU 19 applies a driving voltage from the battery 100 to the electric water pump 14 to operate the electric water pump 14, cuts off the third heater hose 11c, and the fourth heater hose 11d and the first bypass passage 13a. The flow path switching valve 16 is controlled so as to conduct.
[0060]
The operation start timing of the electric water pump 14 and the switching timing of the flow path switching valve 16 are, for example, when an ignition switch (not shown) provided in the passenger compartment is switched from OFF to ON, preferably a vehicle door (preferably For example, when the driver's door is opened, the driver is seated in the driver's seat, and the like.
[0061]
In this case, since the mechanical water pump 10 does not operate and only the electric water pump 14 operates, as shown in FIG. 2, the electric water pump 14 → the second bypass passage 13b → the heat storage tank 15 → the third bypass passage 13c. → first heater hose 11a → first cooling water channel 4 → head side cooling water channel 2a → block side cooling water channel 2b → mechanical water pump 10 → third cooling water channel 8 → fourth heater hose 11d → channel switching valve 16 → first A circulation circuit in which cooling water flows in the order of 1 bypass passage 13a → electric water pump 14 is established.
[0062]
When such a circulation circuit is established, the cooling water discharged from the electric water pump 14 flows into the cooling water inlet 15a of the heat storage tank 15 through the second bypass passage 13b. When the cooling water flows into the cooling water inlet 15a, the cooling water stored in the heat storage tank 15 while being kept warm (hereinafter referred to as heat retaining cooling water) is discharged from the cooling water outlet 15b.
[0063]
The heat insulation cooling water discharged from the cooling water outlet 15b of the heat storage tank 15 flows into the head side cooling water passage 2a of the internal combustion engine 1 through the third bypass passage 13c, the first heater hose 11a, and the first cooling water passage 4. Then, it flows from the head side cooling water channel 2a into the block side cooling water channel 2b.
[0064]
The warm water flowing from the head side cooling water channel 2a to the block side cooling water channel 2b flows through the block side cooling water channel 2b and then flows into the third cooling water channel 8 via the mechanical water pump 10.
[0065]
Thus, when the heat retaining cooling water stored in the heat storage tank 15 flows into the head side cooling water channel 2a and the block side cooling water channel 2b, it originally stayed in the head side cooling water channel 2a and the block side cooling water channel 2b instead of being replaced. Low temperature cooling water is discharged from the head side cooling water channel 2a and the block side cooling water channel 2b. The heat of the heat retaining cooling water is transmitted to the cylinder head 1a and the cylinder block 1b of the internal combustion engine 1.
[0066]
Furthermore, in the circulation circuit as shown in FIG. 2, since the heat-retaining cooling water from the heat storage tank 15 is supplied to the block-side cooling water passage 2b after passing through the head-side cooling water passage 2a, the cylinder head 1a is given priority. Will be preheated. Furthermore, in the circulation circuit as shown in FIG. 2, since there is no member having a large heat capacity such as the heater core 12 in the path from the heat storage tank 15 to the head side cooling water passage 2a, the heat stored in the heat storage tank 15 is unnecessary. The heat is transmitted to the cylinder head 1a without being dissipated.
[0067]
As a result, the wall surface temperature of the intake port (not shown) of the cylinder head 1a, the wall surface temperature of the combustion chamber, etc. quickly increase, fuel vaporization at the start of the engine and immediately after the engine start is promoted, and the temperature of the mixture is increased. It is possible to achieve a reduction in the amount of fuel adhering to the wall surface, stabilization of combustion, improvement of startability, shortening of warm-up operation time, and the like.
[0068]
When the preheating control described above is executed, the temperature of the cooling water circulating in the head side cooling water channel 2a, the block side cooling water channel 2b, the first cooling water channel 4, the third cooling water channel 8, and the bypass water channel 9 rises rapidly. (Hereinafter, the cooling water flowing through the head-side cooling water channel 2a, the block-side cooling water channel 2b, the first cooling water channel 4, the third cooling water channel 8, and the bypass water channel 9 is referred to as engine-side cooling water. The temperature of the cooling water is referred to as the engine side water temperature).
[0069]
Therefore, when a start request is generated while the internal combustion engine 1 is being preheated (for example, when the starter switch is switched from OFF to ON), in other words, the internal combustion engine 1 is started during the execution of the preheat control. In this case, it is necessary to execute fuel injection control while the engine-side water temperature is changing rapidly.
[0070]
In fuel injection control at start-up, for example, the start-up fuel injection amount (TAU) is determined using a start-up fuel injection amount calculation formula as shown below.
[0071]
TAU = TAUSTA * FTHA + TAUV
(TAUSTA: basic injection amount at start, FTHA: intake air temperature correction value, TAUV: invalid injection time)
In the starting fuel injection amount calculation formula, the starting basic injection amount (TAUSTA) is a value determined using the engine-side water temperature correlated with the temperature of the internal combustion engine 1 as a parameter. For example, the engine-side water temperature is low. It is a value that is increased.
[0072]
In the fuel injection control after startup, for example, the fuel injection amount (TAU) is determined using a fuel injection amount calculation formula as shown below.
[0073]
TAU = TP * FWL * (FAF + FG) * [FASE + FAE + FOTP + FDE (D)] * FFC + TAUV
(TP: Basic injection amount, FWL: Warm-up increase, FAF: Air-fuel ratio feedback correction factor, FG: Air-fuel ratio learning coefficient, FASE: Increase after start, FAE: Acceleration increase, FOTP: OTP increase, FDE (D) : Deceleration increase (decrease), FFC: Correction factor at fuel cut return, TAUV: Invalid injection time)
In the fuel injection amount calculation formula as described above, the warm-up increase amount (FWL) and the post-startup increase amount (FASE) are also values determined using the engine side water temperature correlated with the temperature of the internal combustion engine 1 as a parameter. For example, the warm-up increase (FWL) is a value obtained by correcting the correction value corresponding to the engine-side water temperature with a correction coefficient based on the engine speed, and the post-start increase (FASE) is the engine-side water temperature at the start of the engine. The value is determined accordingly.
[0074]
As the engine side water temperature used for such fuel injection control, the output signal value of the engine side water temperature sensor 18 can be used.
[0075]
By the way, a water temperature sensor used in a general vehicle internal combustion engine is designed on the assumption that the actual engine side water temperature change is relatively gentle as in the case where the internal combustion engine is in a normal operation state. In a situation where the engine-side water temperature changes rapidly, such as when the internal combustion engine 1 is heated by the heat retaining cooling water, there may be a case where the actual engine-side water temperature cannot be tracked and a response delay occurs.
[0076]
For example, when the execution of the preheating control is started, the flow path switching valve 16 shuts off the third heater hose 11c and connects the fourth heater hose 11d and the first bypass passage 13a, and the electric water pump 14 operates. . In this case, as shown in FIG. 3, the actual engine-side water temperature rapidly increases after the time until the heat insulation cooling water in the heat storage tank 15 reaches the internal combustion engine 1 (response delay time of the heat insulation cooling water) has elapsed. To rise. On the other hand, the engine-side water temperature sensor 18 cannot follow the rapid increase in the actual engine-side water temperature, so that the output signal value of the engine-side water temperature sensor 18 rises gently.
[0077]
As a result, an error corresponding to the response delay of the engine side water temperature sensor 18 occurs between the actual engine side water temperature and the output signal value of the engine side water temperature sensor 18.
[0078]
However, when the mixing of the engine-side cooling water and the heat-retaining cooling water progresses with the passage of time and the two temperatures converge to substantially the same temperature, the actual change in the engine-side water temperature becomes gentle, so the engine-side water temperature sensor 18 The response delay is eliminated.
[0079]
Therefore, if the internal combustion engine 1 is started during the period from when the preheating of the internal combustion engine 1 is started until the response delay of the engine side water temperature sensor 18 is eliminated, the actual engine side water temperature and the engine side water temperature sensor 18 Depending on the error from the output signal value, the above-mentioned basic injection amount at start (TAUSTA), warm-up increase (FWL), post-start increase (FASE), etc. should be set to optimum values corresponding to the actual engine-side water temperature. It becomes difficult.
[0080]
Therefore, in the present embodiment, when the internal combustion engine 1 is started during the execution of the preheating control, the actual engine-side water temperature is accurately estimated, and control such as fuel injection control is performed using the estimated engine-side water temperature. The value was decided.
[0081]
Hereinafter, a method for estimating the actual engine-side water temperature when preheating control of the internal combustion engine 1 is being performed will be described.
[0082]
In estimating the actual engine-side water temperature, the ECU 19 executes an engine-side water temperature estimation control routine as shown in FIG. This engine-side water temperature estimation control routine is a routine that is executed when the preheating control execution condition of the internal combustion engine 1 is satisfied as a trigger.
[0083]
The preheating control execution conditions are as follows: (1) the internal combustion engine 1 is in a state immediately before starting; (2) the output signal value of the engine side water temperature sensor 18 is less than a predetermined cold determination temperature (for example, 50 ° C.). The conditions such as being can be exemplified.
[0084]
In the engine-side water temperature estimation control routine, the ECU 19 first determines in S401 whether or not the execution of the preheating control has already been started.
[0085]
If it is determined in S401 that the preheating control has not been started, the ECU 19 proceeds to S402, accesses an estimation completion flag storage area preset in the RAM, and stores "0" in the estimation completion flag storage area. "Is written.
[0086]
The estimation completion flag storage area described above is an area where “0” is written when execution of the preheating control is started and is rewritten to “1” when the response delay of the engine-side water temperature sensor 18 is eliminated.
[0087]
In S403, the ECU 19 reads the output signal value of the engine-side water temperature sensor 18 (hereinafter referred to as engine-side water temperature initial value: THWeini) before starting the execution of the preheating control, and stores it in a RAM or the like.
[0088]
In S404, the ECU 19 determines whether or not the execution of the preheating control is started, specifically, whether or not the flow path switching valve 16 is opened and the electric water pump 14 is operated.
[0089]
If it is determined in S404 that the preheating control has not been started, the ECU 19 once ends the execution of this routine.
[0090]
On the other hand, if it is determined in S404 that the preheating control has been started, the ECU 19 proceeds to S405, and estimates the temperature: THWtini of the cooling water (heat-retaining cooling water) that has been stored warmly in the heat storage tank 15. To do. As a method of estimating the heat insulation cooling water temperature: THWtini, the output signal value of the tank outlet water temperature sensor 17 after starting the preheating control, that is, the temperature of the cooling water flowing out of the heat storage tank 15 is regarded as the heat insulation cooling water temperature: THWtini. Can be illustrated.
[0091]
In S406, the ECU 19 calculates the temperature difference between the engine-side water temperature initial value read in S403: THWeini and the heat insulation cooling water temperature estimated in S405: THWtini (hereinafter referred to as initial temperature difference: ΔTte). The calculated initial temperature difference: ΔTte is stored in a RAM or the like.
[0092]
In S407, the ECU 19 sets the initial temperature difference calculated in S406: ΔTte to the amount of cooling water on the internal combustion engine 1 side (head side cooling water channel 2a, block side cooling water channel 2b, first cooling water channel 4, third cooling water channel). 8, the total capacity of the cooling water existing in the bypass water passage 9, the first heater hose 11a, the fourth heater hose 11d, the first bypass passage 13a, the second bypass passage 13b, and the third heater hose 11c). A coefficient representing the ratio between the added value and the flow rate of cooling water supplied from the heat storage tank 15 to the internal combustion engine 1 per unit time: divided by A, and the amount of heat transferred from the heat retaining cooling water to the engine side cooling water: ΔTHWa is calculated.
[0093]
Here, the flow rate of the cooling water supplied from the heat storage tank 15 to the internal combustion engine 1 per unit time (hereinafter referred to as the heat retention cooling water flow rate) is such that the heat retaining heat medium flowing out of the heat storage tank 15 is the head side of the internal combustion engine 1. The time required to reach the cooling water channel 2a (hereinafter referred to as the time required for reaching the heat retaining heat medium) can be obtained as a parameter. That is, the heat retention cooling water flow rate increases as the heat insulation heat medium arrival time decreases, and the heat insulation cooling water flow rate decreases as the heat insulation heat medium arrival time increases.
[0094]
When determining the time required to reach the heat insulation heat medium, the ECU 19 first specifies the time when the heat insulation cooling water flows out of the heat storage tank 15 (hereinafter referred to as heat insulation cooling water outflow time), and then the heat insulation cooling water is supplied to the head. The time at which the side cooling water channel 2a is reached (hereinafter referred to as the heat insulation cooling water arrival time) is specified.
[0095]
When specifying the heat insulation cooling water outflow time, the ECU 19 stores the output signal value of the tank outlet water temperature sensor 17 (hereinafter referred to as tank outlet water temperature initial value: THWex1) immediately before the start of the preheating control and stores the preheating. The output signal value of the tank outlet water temperature sensor 17 (hereinafter referred to as tank outlet water temperature: THWex2) is monitored after the start of control execution, and the tank outlet water temperature: THWex2 is higher than the tank outlet water temperature initial value: THWex1 by a certain temperature or more. Is identified as the warming cooling water outflow time.
[0096]
This is because the temperature of the cooling water in the vicinity of the tank outlet water temperature sensor 17 rises when the heat retaining cooling water in the heat storage tank 15 flows out of the cooling water outlet 15b.
[0097]
When specifying the heat insulation cooling water arrival time, the ECU 19 stores the output signal value (engine side water temperature initial value: THWeini) of the engine side water temperature sensor 18 immediately before the start of the preheating control, and after the start of the preheating control. The engine-side water temperature sensor 18 output signal value (hereinafter referred to as engine-side water temperature: THWe) is monitored, and the engine-side water temperature: THWe becomes the engine-side water temperature initial value: THWeini. Specify arrival time.
[0098]
This is because when the high temperature heat retaining cooling water flowing out from the heat storage tank 15 reaches the head side cooling water passage 2a, the cooling water temperature in the vicinity of the engine side water temperature sensor 18 is increased.
[0099]
By the way, before the start of the preheating control, a part of the path (the third bypass passage 13c, the first heater hose 11a, and the first cooling water passage 4) from the heat storage tank 15 to the internal combustion engine 1 is located near the engine side water temperature sensor 18. If cooling water having a temperature higher than that of the cooling water exists, the output signal value (engine-side water temperature: THWe) of the engine-side water temperature sensor 18 when the high-temperature cooling water reaches the vicinity of the engine-side water temperature sensor 18 is the engine-side water temperature. Initial value: May be higher than THWeini by a certain temperature.
[0100]
In this case, the ECU 19 has reached the head-side cooling water channel 2a while the heat-retaining heat medium from the heat storage tank 15 has reached the head-side cooling water channel 2a even though the heat-retaining cooling water from the heat storage tank 15 has not actually reached the head-side cooling water channel 2a. It will be erroneously determined.
[0101]
When such an erroneous determination occurs, the required time for reaching the heat insulation heat medium calculated by the ECU 19 becomes shorter than the actual time required for reaching the heat insulation heat medium, and the flow rate of the heat insulation cooling water estimated by the ECU 19 is thus reduced. More than the flow rate.
[0102]
When the heat insulation cooling water flow rate estimated by the ECU 19 is larger than the actual heat insulation cooling water flow rate, it is presumed that the engine side water temperature is higher than the actual engine water temperature, and the above-described basic injection amount at start (TAUSTA) ), Warm-up increase (FWL), post-startup increase (FASE), and the like are assumed to be inappropriate values with respect to the actual engine-side water temperature, so that it is assumed that the controllability of the internal combustion engine 1 is reduced.
[0103]
On the other hand, in the internal combustion engine provided with the heat storage device in the present embodiment, an upper limit value is provided for the heat insulation cooling water flow rate used for engine side water temperature estimation control, and the heat insulation cooling water flow rate estimated by the ECU 19 satisfies the upper limit value. In the case of exceeding, the engine-side water temperature is estimated using the above-described upper limit value as the heat-retaining cooling water flow rate.
[0104]
Specifically, the ECU 19 estimates the heat insulation cooling water flow rate by executing a heat insulation cooling water flow rate estimation control routine as shown in FIG. This thermal insulation cooling water flow rate estimation control routine is a routine that is executed when the preheating control execution condition of the internal combustion engine 1 is satisfied as a trigger.
[0105]
In the heat insulation cooling water flow rate estimation control routine, the ECU 19 first outputs the output signal value of the tank outlet water temperature sensor 17 (tank outlet water temperature initial value: THWex1) and the output signal value of the engine side water temperature sensor 18 immediately before the start of the preheating control in S501. (Engine side water temperature initial value: THWeini) is read and stored in RAM or the like.
[0106]
In S502, the ECU 19 determines whether or not the execution of the preheating control has been started.
[0107]
When it is determined in S502 that the execution of the preheating control has not been started, the ECU 19 repeatedly executes the process of S502 until the execution of the preheating control is started.
[0108]
If it is determined in S502 that the preheating control has been started, the ECU 19 proceeds to S503 and reads the output signal value of the tank outlet water temperature sensor 17 (tank outlet water temperature: THWex2).
[0109]
In S504, the ECU 19 reads out the tank outlet water temperature initial value: THWex1 read in S501 from the RAM, and compares the tank outlet water temperature initial value: THWex1 with the tank outlet water temperature: THWex2 read in S503.
[0110]
Specifically, the ECU 19 determines whether or not a value (= THWex2-THWex1) obtained by subtracting the tank outlet water temperature initial value: THWex1 from the tank outlet water temperature: THWex2 is equal to or higher than a certain temperature: t.
[0111]
When it is determined in S504 that the value obtained by subtracting the tank outlet water temperature initial value: THWex1 from the tank outlet water temperature: THWex2 (= THWex2-THWex1) is less than the constant temperature: t, the ECU 19 performs the above-described S503. The subsequent processing is executed again.
[0112]
When it is determined in S504 that the value (= THWex2-THWex1) obtained by subtracting the tank outlet water temperature initial value: THWex1 from the tank outlet water temperature: THWex2 is equal to or higher than the constant temperature: t, the ECU 19 It is assumed that the heat retaining cooling water inside has flowed out from the cooling water outlet 15b (that is, the current time is regarded as the heat retaining cooling water outflow timing), and the counter: C is started in S505. The counter C is a counter that measures an elapsed time from the heat-insulating cooling water outflow timing.
[0113]
In S506, the ECU 19 reads the output signal value of the engine side water temperature sensor 18 (engine side water temperature: THWe).
[0114]
In S507, the ECU 19 reads the engine side water temperature initial value: THWeini read in S501 from the RAM, and compares the engine side water temperature initial value: THWeini with the engine side water temperature: THWe read in S506.
[0115]
Specifically, the ECU 19 determines whether or not a value (= THWe−THWeini) obtained by subtracting the engine side water temperature initial value: THWeini from the engine side water temperature: THWe is equal to or higher than a constant temperature: t.
[0116]
If it is determined in S507 that the value obtained by subtracting the engine-side water temperature: THWeini from the engine-side water temperature: THWe (= THWe-THWeini) is less than the constant temperature: t, the ECU 19 performs the above-described S506. The subsequent processing is executed again.
[0117]
If it is determined in S507 that the value obtained by subtracting the engine-side water temperature: THWeini from the engine-side water temperature: THWeini (= THWe-THWeini) is equal to or higher than the constant temperature: t, the ECU 19 Has reached the head-side cooling water channel 2a (that is, the current time is considered to be the time for reaching the heat insulation cooling water), and in S508, the counter: C measurement time: C is stored in the RAM as the heat insulation heat medium arrival time.
[0118]
In S509, the ECU 19 determines the time required to reach the heat retaining heat medium determined in S508 and the path from the heat storage tank 15 to the head side cooling water path 2a (the third bypass path 13c, the first heater hose 11a, and the first cooling water path). From the distance of 4), heat insulation cooling water flow rate: fv is calculated.
[0119]
In S510, the ECU 19 determines whether or not the heat retention cooling water flow rate fv calculated in S509 is equal to or less than an upper limit value fvmax.
[0120]
Here, the upper limit value: fvmax is determined using at least one of the engine side water temperature initial value: THWeini, the outside air temperature (for example, the output signal value of the outside air temperature sensor, the intake air temperature sensor, etc.) and the output voltage of the battery 100 as parameters. Value.
[0121]
For example, as shown in FIG. 6, the upper limit value: fvmax may be a larger value as the engine side water temperature initial value: THWeini is higher, and may be a smaller value as the engine side water temperature initial value: THWeini is lower.
[0122]
This is because the viscosity of the cooling water increases as the temperature decreases, and the viscosity decreases as the temperature increases. Therefore, the cooling water flow rate tends to decrease as the cooling water temperature decreases, and the cooling water increases as the cooling water temperature increases. This is because the flow velocity tends to be high.
[0123]
Further, as shown in FIG. 7, the upper limit value fvmax may be set to a larger value as the outside air temperature becomes higher, and may be set to a smaller value as the outside air temperature becomes lower.
[0124]
This is because the temperature of the cooling water tends to be low (the viscosity of the cooling water tends to be high) as the outside air temperature is low, and the temperature of the cooling water tends to be high (the viscosity of the cooling water tends to be low) as the outside air temperature is high. Therefore, the lower the outside air temperature, the lower the flow rate of the cooling water, and the higher the outside air temperature, the higher the flow rate of the cooling water.
[0125]
Further, as shown in FIG. 8, the upper limit value fvmax may be a larger value as the output voltage of the battery 100 is higher, and a smaller value as the output voltage of the battery 100 is lower.
[0126]
This is because the discharge amount of the electric water pump 14 decreases as the output voltage of the battery 100 decreases, and the discharge amount of the electric water pump 14 increases as the output voltage of the battery 100 increases, so that the output voltage of the battery 100 decreases. This is because the flow rate of the cooling water tends to increase and the flow rate of the cooling water tends to increase as the output voltage of the battery 100 increases.
[0127]
Here, returning to FIG. 5, when it is determined in S510 that the heat retention cooling water flow rate: fv is not more than the upper limit value: fvmax, the ECU 19 uses the heat retention cooling water flow rate: fv calculated in S509. The flow rate is stored in the RAM, and the execution of this routine is terminated.
[0128]
On the other hand, if it is determined in S510 that the heat retention cooling water flow rate: fv exceeds the upper limit value: fvmax, the ECU 19 stores the upper limit value: fvmax in the RAM as the heat retention cooling water flow rate, and executes this routine. Exit.
[0129]
As described above, when the ECU 19 executes the flow rate calculation control routine as shown in FIG. 5, even if the heat insulation cooling water arrival time is erroneously determined, the estimated value of the heat insulation cooling water flow rate is the actual heat insulation cooling water. It will not be excessive with respect to the flow rate.
[0130]
Returning to FIG. 4, in S407 described above, the amount of heat transferred from the heat retaining cooling water to the engine side cooling water: ΔTHWa is calculated using the heat retaining cooling water flow rate estimated according to the flow rate estimation control routine. Then, the ECU 19 proceeds to S408.
[0131]
In S408, the ECU 19 accesses the estimation completion flag storage area of the RAM, and determines whether “1” is not stored.
[0132]
When it is determined in S408 that “1” is stored in the estimation completion flag storage area of the RAM, the ECU 19 considers that it is not necessary to estimate the engine-side water temperature, and ends the execution of this routine.
[0133]
On the other hand, if it is determined in S408 that “1” is not stored in the estimation completion flag storage area of the RAM, that is, if it is determined that “0” is stored in the estimation completion flag storage area, the ECU 19 Advances to S409.
[0134]
In S409, the ECU 19 determines whether or not an elapsed time from the start of execution of the preheating control (hereinafter referred to as preheating control execution time) is less than a predetermined time: Time. The predetermined time: Time is a time corresponding to the response delay time of the engine-side water temperature sensor 18.
[0135]
The response delay time of the second engine-side water temperature sensor 18 changes in accordance with the engine-side water temperature initial value: THWeini and the heat insulation cooling water temperature: THWtini, so the response delay time of the engine-side water temperature sensor 18 and the engine-side water temperature The relationship between the initial value: THWeini and the heat insulation cooling water temperature: THWtini may be experimentally obtained in advance, and the relationship may be mapped.
[0136]
If it is determined in S409 that the preheating control execution time is equal to or greater than the predetermined time: Time, the ECU 19 regards that the response delay of the engine-side water temperature sensor 18 has already been eliminated, and ends the execution of this routine. To do.
[0137]
If it is determined in S409 that the preheating control execution time is less than the predetermined time: Time, the ECU 19 regards that the response delay of the engine-side water temperature sensor 18 has not yet been resolved, and proceeds to S410.
[0138]
In S410, the ECU 19 executes an attenuation process of the amount of heat: ΔTHWa transferred per unit time from the heat retaining cooling water to the engine side cooling water. This is because when the elapsed time from the start of preheating control increases, the temperature difference between the heat retaining cooling water and the engine side cooling water decreases, and the amount of heat transferred from the heat retaining cooling water to the engine side cooling water also increases. This is because it will decrease.
[0139]
In the attenuation process of the heat quantity: ΔTHWa, for example, the ECU 19 adds a predetermined attenuation coefficient: B to the heat quantity calculated during the previous execution of this routine: ΔTHWa-1 to obtain a new heat quantity: ΔTHWa. calculate. The damping coefficient B described above is between the heat insulation cooling water and the engine side cooling water in consideration of the amount of the heat insulation cooling water, the amount of the engine side cooling water, the heat capacity of the path through which the cooling water flows, and the heat insulation cooling water flow rate. This is a value that simulates the transfer of heat performed in step 1. For example, the value is less than “1”. The attenuation coefficient B may be a fixed value, but may be a variable value that is changed according to the preheating control execution time.
[0140]
When the S410 is executed for the first time after the start of the preheating control, the ECU 19 sets the heat amount calculated in S407: ΔTHWa as a new heat amount: ΔTHWa as it is.
[0141]
In S411, the ECU 19 estimates the actual temperature of the engine-side cooling water using the new heat amount calculated in S410: ΔTHWa. Specifically, the ECU 19 first reads out the engine-side water temperature initial value: THWeini read in S403 from the RAM, and at the same time, keeps the warm water flow rate estimated in the flow rate estimation control routine of FIG. The new heat quantity calculated in this way: ΔTHWa, the preheating control execution time, and a predetermined coefficient: C are integrated (heat insulation cooling water flow rate * preheating control execution time * ΔTHWa * C). Subsequently, the ECU 19 adds the engine side water temperature initial value: THWeini and the integrated value (heat insulation cooling water flow rate * preheating control execution time * ΔTHWa * C) to estimate the actual engine side water temperature (hereinafter referred to as “the estimated engine side water temperature”). , Actual engine side water temperature estimated value: referred to as THWb).
[0142]
Here, the above-mentioned coefficient C is a coefficient in consideration of the amount of heat transferred from the internal combustion engine 1 to the cooling water and the delay of the heat mass. However, before the engine is started, combustion is not performed in the internal combustion engine 1 and heat transmitted from the internal combustion engine 1 to the cooling water is not generated. Therefore, the value of the coefficient C can be changed before and after the engine is started. preferable.
[0143]
In S412, the ECU 19 reads the output signal value (engine-side water temperature: THWe) of the engine-side water temperature sensor 18 at the current time.
[0144]
In S413, the ECU 19 determines whether or not the actual engine side water temperature estimated value THWb calculated in S411 is equal to the engine side water temperature sensor value THTH read in S412.
[0145]
If it is determined in S413 that the actual engine-side water temperature estimated value THWb and the engine-side water temperature sensor value THTH are not equal, the ECU 19 considers that the response delay of the engine-side water temperature sensor 18 has not been eliminated, and S414. Proceed to
[0146]
In S414, the ECU 19 stores the actual engine-side water temperature estimated value: THWb as a current engine-side water temperature in a predetermined area of the RAM, and ends the execution of this routine.
[0147]
On the other hand, when it is determined in S413 that the actual engine-side water temperature estimated value: THWb is equal to the engine-side water temperature sensor value: THWe, the ECU 19 regards that the response delay of the engine-side water temperature sensor 18 has been eliminated, and proceeds to S415. move on.
[0148]
In S415, the ECU 19 stores the engine-side water temperature sensor value: THWe in the predetermined area of the RAM as the engine-side water temperature at the present time.
[0149]
Subsequently, the ECU 19 proceeds to S416, accesses the estimation completion flag storage area of the RAM, and rewrites the value of this estimation completion flag storage area from “0” to “1”.
[0150]
The ECU 19 thus executes the engine-side water temperature estimation control routine, so that the actual engine-side water temperature: THWb is estimated on the basis of the engine-side water temperature initial value: THWeini, the heat insulation cooling water temperature: THWtini, and the heat insulation cooling water flow rate: fv. Therefore, it is possible to improve the estimation accuracy of the actual engine side water temperature estimated value: THWb.
[0151]
As a result, when the internal combustion engine 1 is started during the execution of the preheating control, particularly when the internal combustion engine 1 is started under the situation where the response delay of the engine-side water temperature sensor 18 occurs during the execution of the preheating control. Since the actual engine side water temperature estimated value: THWb is used as the engine side water temperature used for fuel injection control, the basic injection amount at start (TAUSTA), warm-up increase (FWL), and increase after start ( FASE) can be set to a value suitable for the actual engine water temperature.
[0152]
Furthermore, in this embodiment, since an upper limit value is set for the estimated value of the heat insulation cooling water flow rate, the estimated value of the heat insulation cooling water flow rate is the actual heat insulation cooling water flow rate even if the heat insulation cooling water arrival time is erroneously determined. The actual engine-side water temperature estimated value estimated using the heat-reducing cooling water flow rate as a parameter: THWb does not become excessively higher than the actual engine-side water temperature.
[0153]
As a result, even if the actual engine-side water temperature estimate: THWb is used as a parameter to determine the starting basic injection amount (TAUSTA), warm-up increase (FWL), post-starting increase (FASE), etc., the basic injection at startup The amount (TAUSTA), warm-up increase (FWL), post-start increase (FASE), etc., do not become excessively far from the appropriate values corresponding to the actual engine-side water temperature.
[0154]
In this embodiment, an example in which a guard value is set for the heat-retaining cooling water flow rate has been described. However, a guard value may be set for the actual engine-side water temperature estimated value instead of the heat-retaining cooling water flow rate. .
[0155]
For example, the processing of S510 to S512 is deleted in the flow rate estimation control routine of FIG. 5 described above, and the actual engine side water temperature estimated value: THWb is used instead of the processing of S414 in the engine side water temperature estimation control routine of FIG. Engine side water temperature: If the value obtained by subtracting THWe is less than the specified value, the actual engine side water temperature estimate: THWb is set as the current engine side water temperature, and the actual engine side water temperature estimate: THWb to the engine side water temperature : When the value obtained by subtracting THWe exceeds a specific value, engine-side water temperature: a process of setting the temperature obtained by adding the specific value to THWe as the engine-side water temperature at the present time may be added.
[0156]
Further, in the present embodiment, the fuel injection control is exemplified as the control that uses the output signal value of the engine-side water temperature sensor 18, but the present invention is not limited to this, and the ignition control, the idle speed control ( It may be ISC (Idle Speed Control), exhaust gas recirculation (EGR) control, or the like.
[0157]
【The invention's effect】
In the internal combustion engine provided with the heat storage device according to the present invention, when the estimated value of the flow rate of the heat retaining heat medium supplied from the heat storage tank to the internal combustion engine is not exceeded the specific value, the heat retaining heat medium flow rate is erroneously estimated. Even so, the estimated value of the heat retaining heat medium flow rate supplied from the heat storage tank to the internal combustion engine does not excessively increase with respect to the actual heat retaining heat medium flow rate.
[0158]
As a result, the temperature of the internal combustion engine is not considered to be excessively higher than the actual temperature, so that a decrease in controllability of the internal combustion engine is suppressed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a cooling system of an internal combustion engine to which the present invention is applied.
FIG. 2 is a diagram showing a cooling water circulation mode during preheating control.
FIG. 3 is a diagram showing a response delay of the engine-side water temperature sensor when preheating control is executed.
FIG. 4 is a flowchart showing an engine-side water temperature estimation control routine.
FIG. 5 is a flowchart showing a flow rate estimation control routine.
[Figure 6] Diagram showing the relationship between upper limit value: fvmax and engine side water temperature initial value: THWeini
FIG. 7 is a diagram showing the relationship between the upper limit value: fvmax and the outside air temperature.
FIG. 8 is a graph showing the relationship between the upper limit value: fvmax and the output voltage of the battery.
[Explanation of symbols]
1 ... Internal combustion engine
1a ... Cylinder head
1b ... Cylinder block
2a: Head side cooling water channel
2b Block side cooling water channel
10 ... Mechanical water pump
14 ... Electric water pump
15 ... Thermal storage tank
17 ... Tank outlet water temperature sensor
18 ... Engine side water temperature sensor
19 ... ECU

Claims (3)

Engine side temperature detecting means for detecting the temperature of the heat medium flowing through the internal combustion engine;
Tank-side temperature detection means for detecting the temperature of the heat medium inside or at the outlet of the heat storage tank;
By supplying the heat medium body to the internal combustion engine from thermal storage tank before the start of the internal combustion engine, the preheating control means for preheating the internal combustion engine,
Based on the detected value of the detection value and the tank temperature detecting means of the engine-side temperature detecting means estimates the flow rate of the heat medium supplied from the thermal storage tank to the internal combustion engine in a preheated execution by the preheating control means heat Medium flow rate estimation means;
When the estimated amount of the heat medium flow rate estimating means is not more than a specific value, the estimated amount is set as the flow rate of the heat medium, and when the estimated value of the heat medium flow rate estimating means exceeds the specific value, the specific value is A heat medium flow rate guard means for setting the flow rate of the medium;
Difference when said internal combustion engine in a preheated execution by preheating means is started, the preheating control means detected value before Symbol engine side temperature sensing hand stage and before Symbol tank temperature detecting hands stage before starting preheating is detected by And control value determining means for determining a control value related to control of the internal combustion engine according to a set value of the heat medium flow guard means,
An internal combustion engine provided with a heat storage device. Engine side temperature detecting means for detecting the temperature of the heat medium flowing through the internal combustion engine;
Tank-side temperature detection means for detecting the temperature of the heat medium inside or at the outlet of the heat storage tank;
By supplying the heat medium body to the internal combustion engine from thermal storage tank before the start of the internal combustion engine, the preheating control means for preheating the internal combustion engine,
Based on the detected value of the detection value and the tank temperature detecting means of the engine-side temperature detecting means estimates the flow rate of the heat medium supplied from the thermal storage tank to the internal combustion engine in a preheated execution by the preheating control means heat Medium flow rate estimation means;
The difference between the pre-heating control means detected value before Symbol engine side temperature sensing hand stage and before Symbol tank temperature detecting hand stage is detected before starting preheating by, and based on the estimated value of the heat medium flow rate estimation means, an internal combustion engine An actual engine side temperature estimating means for estimating the actual temperature of the heat medium flowing through
When the deviation between the detected value of the engine side temperature detecting means and the estimated value of the actual engine side temperature estimating means is less than a specific value, the estimated value of the actual engine side temperature estimating means is set as the engine side temperature, When the deviation between the detected value of the engine side temperature detecting means and the estimated value of the actual engine side temperature estimating means exceeds a specific value, the value obtained by adding the specific value to the detected value of the engine side temperature detecting means Engine side temperature guard means to set as
If the internal combustion engine is started in a preheated execution by said preheating means includes a control value determining means for determining a control value related to control of the internal combustion engine according to the set value before Symbol engine-side temperature guard means,
An internal combustion engine provided with a heat storage device.   3. The specific value is set based on at least one of an outside air temperature, a battery voltage, and a temperature detected by a temperature detecting means at the start of supply of the heat medium from the heat storage tank to the internal combustion engine. An internal combustion engine comprising the heat storage device according to 1.

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